# Is there a pitch maneuver in launch vehicle trajectory to raise the perigee altitude in order to circularize?

What is the purpose of the pitch manoeuvre that is being executed here in the following Vega launch video?

Similar manoeuvre in the following Antares launch video as well:

Is it for raising the perigee of the orbit i.e. to circularize the trajectory or some other purpose?

What are the trajectory manoeuvres available for circularizing the multi-stage launch vehicle trajectory?

You can think about it (approximately) by dividing the rocket trajectory into "up" and "downrange" parts. The "downrange" part is the largest one: To get to orbit, the rocket has to generate a lot of speed in that direction.

The "up" part is quite different. To end up in a low, circular orbit, the rocket has to go "up" few hundred kilometers and stop.

If you just treat this a parabolic motion, "I'll build up some vertical speed and coast up until gravity stops me", that's fine for a high orbit: You blast out of the atmosphere and eventually stop at the right height. But it's not great if your orbit is a low one: To keep the vertical speed low enough (still fast, but comparatively slower than the first example), you spend a lot of time in the first part, still in the atmosphere. And that causes drag losses and heating you don't want.

So the first part of the flight builds up a lot of vertical speed to get you out fast. Now you're got too much vertical speed to end up in the right circular orbit, so later in flight you add a downwards component to the thrust so that you arrive at the right final altitude and stop.